Timed Popups

PC running XP Pro.

using firefox (latest version)

Earlier this evening i started getting regular popups that seem to be set to a time (around 4 minutes apart). It loads firefox and resizes it as necessary. If i'm already browsing it opens it in another tab, but still resizes the window.

On top of this i've got flash animations popping up .. although this is less regular.

I'm not the only user of this computer and i'm therefore not sure who's loaded what.

I've been trying with my intermediate knowledge of computers for a couple of hours on and off now and don't seem to be having any luck at all.

I'd apreciate it if anyone can point me in the right direction.

I have tried the following :

startup folder on start menu (empty) msconfig-startup - nothing in there is loading now nothing unusual in system.ini or win.ini Had a slightly detailed look through the registry, removed a few things that looked possitive. made no difference. I've had to delete a couple of small apps that must have been loaded with whatever this is. This has also made no difference

Theres nothing unusual on the task manager (apps or processes)

I've run spybot and whilst there was alot there that has nw been removed it has not stopped this. after each major process i've rebooted the machine to confirm things and still i have the problem.

As i say it seems something has been loaded manually by someone which has set this running. I can normally clear anything like this up in a matter of minutes but this one isn't going anywhere.

ANY help at all is greatly appreciated.

Rob